Angiography procedures often use catheters manipulated with the assistance of wires such as shaped wires, micro wires and glide wires. Such wires allow a practitioner (e.g., a physician, surgeon, or nurse) to guide a catheter within vasculature of a patient being imaged (e.g., to guide the catheter into an appropriate blood vessel). Manipulating such wires may be difficult with gloved hands.
One task that may be difficult to perform is threading a shaped wire into a catheter. This task may be required at the beginning of a procedure, or when a procedure requires removal and re-insertion of the wire. Usually an insertion tool resembles a short, hollow cylinder: a wire is loaded into the cylinder and pushed through it into the catheter. In some cases, loading the wire involves pushing a proximal (e.g., patient) end of the wire into the cylinder. However, some wires have a curved proximal end that does not easily insert into the cylinder; in these cases, a distal end of the wire is threaded into a proximal end of the cylinder, and the device is manipulated along the full length of the wire to insert the curved end of the wire into an open end of the catheter. Once insertion is complete, the device is manipulated along the full length of the wire and removed. Guide wires may be over 100 cm in length, so threading the insertion device on, off and along the wire may consume enough time that this time has to be factored into a practitioner's decision to remove and re-engage the wire during a procedure. Re-insertion also provides an unwanted opportunity to drop or contaminate the wire. Also, threading a full length of the wire increases risk of damaging or stripping special coatings (e.g., coatings that allow them to move smoothly within the catheter) of certain wires.
Once a wire is installed in a catheter, the practitioner may need to push, pull and/or twist the wire to direct the wire and the catheter within the subject. Existing torque devices may be helpful in directing the wire, but as with the insertion tool, the torque device must be threaded onto the distal (straight) end of the wire, which may also be time consuming.
FIG. 1A shows a perspective view of one prior art device 10 for manipulating a wire (not shown). Device 10 is made of plastic and has a cap 20 and a handle element 30, as shown. Handle element 30 has a handle 40 coupled with a cylindrical element 50 and segmented cylinder elements 60(1)-60(4). Cylindrical element 50 has threads 55. Handle element 30 forms a central hole (see FIG. 1B) about a wire path 5. Cap 20 has a cylindrical portion 70 and a conical portion 72. Cap 20 forms a central hole 74 along wire path 5. Threads 55 engage corresponding threads inside cap 20, such that cap 20 can screw onto handle element 30. Handle 40 and/or cylindrical portion 70 may have gripping features 45, as shown.
FIG. 1B shows an end view of handle element 30, as seen from cap 20. Each of segmented cylinder elements 60(1)-60(4) is separated from two other such elements by a slot 75, as shown. Wire path 5 (not labeled in FIG. 1B) passes through a central hole 15. In use, a practitioner threads a wire through hole 15 and hole 74 and then screws cap 20 onto handle element 30, forcing elements 60(1)-60(4) into conical portion 72 and squeezing elements 60(1)-60(4) together about the wire. This holds the wire in place so that the practitioner can manipulate the wire by manipulating handle 40.
Other devices for manipulating a wire are shown in U.S. Pat. No. 6,533,772 to Sherts et al., which is incorporated herein by reference.
An aneurysm is a localized dilation of a blood vessel caused by disease or weakening of the vessel wall, and may form a “balloon” shape projecting from the vessel. Rupture of a cerebral aneurysm may cause a stroke. Aneurysm clips are sometimes used to close off an aneurysm to prevent its rupture. Diagnosis and post-treatment assessment of aneurysms may utilize angiography.
FIG. 2A shows a top view of one prior art aneurysm clip 80. Clip 80 is made of titanium, for example. Clip 80 has a spring 82 that biases jaws 86(1) and 86(2) into a closed position. A practitioner applying clip 80 uses an aneurysm clip applicator (e.g., as shown in FIG. 3A and FIG. 3B, or FIG. 18A and FIG. 18B) to squeeze clip 80 at points 84, forcing jaws 86(1) and 86(2) apart so that they may be positioned about a base of an aneurysm. The practitioner utilizes the applicator to manipulate clip 80 until the clip is positioned with jaws 86(1) and 86(2) on either side of the aneurysm, whereupon the practitioner releases the applicator from points 84, returning jaws 86(1) and 86(2) to the closed position and freeing the applicator from clip 80. FIG. 2B shows a side view of clip 80; relative to FIG. 2A, clip 80 is rolled towards the viewer so that jaw 86(1) is in front of, and blocks view of, jaw 86(2).
Because aneurysm clip 80 is made of metal, it may introduce unwanted “flare” and other artifacts into computerized tomography (“CT”) and CT angiography images made after its installation. Such artifacts may obscure important details in the images (for example, details relating to residual aneurysm) and generally interfere with interpretation of the images. Furthermore, clip 80, if manufactured of certain materials (e.g., cobalt alloy steel) may be moved by a strong magnetic field such as the 3 Tesla field of magnetic resonance (“MR”) systems currently being installed in clinical practices. Movement of clip 80 presents a risk of injury or death to a patient.
FIG. 3A and FIG. 3B show a prior art aneurysm clip applicator 1210 in “open” and “closed” positions respectively. Applicator 1210 has handles 1260(1) and 1260(2) that a practitioner compresses to “open” an aneurysm clip 1205. Applicator 1210 also has a flat spring 1275, and latch portions 1220(1) and 1220(2) (attached to handles 1260(1) and 1260(2) respectively). In FIG. 3A, handles 1260(1) and 1260(2) and spring 1275 are not compressed, and applicator 1210 is in an “open” position with jaws 1240(1) and 1240(2) in a position to grab and manipulate clip 1205 (which is in a “closed” position). Pivot points 1230 and 1250 allow movement of applicator 1210 from the “open” position shown in FIG. 3A to the “closed” position shown in FIG. 3B. Latch portions 1220(1) and 1220(2) are disengaged while applicator 1210 is in the “open” position.
In FIG. 3B, handles 1260(1) and 1260(2), and spring 1275 have been compressed by a practitioner, placing jaws 1240(1) and 1240(2) in the “closed” position, and clip 1205 in the “open” position. When jaws 1240(1) and 1240(2) are in the “closed” position, the practitioner may engage latch portions 1220(1) and 1220(2), as shown, to keep them in the “closed” position without the practitioner having to maintain pressure on handles 1260(1) and 1260(2). When clip 1205 is in a final position for clipping an aneurysm, the practitioner must compress handles 1260(1) and 1260(2) in order to disengage latch portion 1220(1) from 1220(2) to close clip 1205. The additional compression motion required by the practitioner to disengage latch portions 1220(1) and 1220(2) may be disadvantageous because it may “jiggle” clip 1205, potentially causing clip 1205 to be misplaced relative to its intended placement. Some practitioners bend off latch portions 1220(1) and/or 1220(2) in order to avoid such a motion. However, when latch portions 1220(1) and/or 1220(2) are bent off, the practitioner must maintain pressure on handles 1260(1) and 1260(2) to keep them in the “closed” position, which may impair the practitioner's ability to maneuver clip 1205 and may again result in misplacement of clip 1205.